Give Blogger tables inline borders

Blogger themes ship no table styling, so the quote tables rendered as
borderless text. Inline styles survive every theme and the mobile view.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

us2kr/deliver/blogger.py

@@ -28,6 +28,17 @@ TOKEN_SAFETY_MARGIN_SECONDS = 60.0
 
 _MD = md.Markdown(extensions=["tables"], output_format="html")
 
+# Blogger themes ship no <table> styling, so the numbers render as a borderless jumble.
+# Inline styles are the only thing every theme (and the mobile view) reliably honors.
+_TABLE_STYLES: tuple[tuple[str, str], ...] = (
+    ("<table>", '<table style="border-collapse:collapse;margin:10px 0;">'),
+    (
+        "<th>",
+        '<th style="border:1px solid #ccc;padding:4px 10px;background:#f2f2f2;text-align:left;">',
+    ),
+    ("<td>", '<td style="border:1px solid #ccc;padding:4px 10px;white-space:nowrap;">'),
+)
+
 
 def briefing_html(markdown_text: str) -> str:
     """Briefing markdown -> HTML body. The leading H1 is dropped (the post title carries it)."""
@@ -35,7 +46,10 @@ def briefing_html(markdown_text: str) -> str:
     if lines and lines[0].startswith("# "):
         lines = lines[1:]
     _MD.reset()  # the converter keeps per-document state (e.g. reference links)
-    return _MD.convert("\n".join(lines).strip())
+    html = _MD.convert("\n".join(lines).strip())
+    for plain, styled in _TABLE_STYLES:
+        html = html.replace(plain, styled)
+    return html
 
 
 def post_title_prefix(result: BriefingResult) -> str: